[MPlayer-users] mencoder frame dropping inconsistencies, depending on audio source??

[D Richard Felker III]

On Sat, Mar 27, 2004 at 10:48:09AM -0500, Charles Wilcox wrote:
> I am trying to solve some audio-video sync problems in DivX files created
> from DVD source.  Specifically, I'm trying to figure out what governs the
> varying output length of each video and audio track.
> 
> Outside of this general annoyance, I have discovered (at least for few
> DVDs I have) mencoder will choose different sequences of frames to drop,
> and will sometimes drop a different number of frames, depending on if I
> tell the "output audio codec" to copy the raw AC3 audio stream, or to copy
> the frameno.avi stream created with the mp3lame codec.
> 
> This really does not make sense to me.  Could someone provide some useful
> insight??  I've attached a copies of the output as an explicit example.
> Also, I did -dumpstream on the DVD track previously, to eliminate the
> possibility of a mis-behaving DVD reader.

Yes, it's buggy. If your DVD is clean (no mix of framerates, etc.) you
can use -mc 0 -noskip to turn off the buggy a/v sync code. Also, don't
use 3pass mode (frameno.avi). It's known to cause a/v desync. Just
encode with lame twice (on both pass1 and pass2).

Rich